Alimentary allergy to pork. Crossreactivity among pork kidney and pork and lamb gut.

BACKGROUND

A patient suffered from anaphylaxis after the ingestion of pork gut and kidney, but she tolerated pork meat. Clinical symptoms were also triggered upon intake of lamb gut.

OBJECTIVE

To demonstrate an IgE-mediated hypersensitivity and identify the pork proteins involved. And also, to study the possible cross-allergenicity among proteins from lamb gut and pork.

METHODS AND RESULTS

The patient had strong positive skin-prick test responses to pork kidney, gut and liver, and lamb gut and kidney. RAST technique showed specific IgE to pork kidney, gut and meat. Immunoblotting after SDS-PAGE disclosed the presence of four prominent IgE-binding polypeptides in pork kidney (200, 90, 57, and 47 kDa), two in gut (57 and 27 kDa), and three in meat (51, 40, and 28-30 kDa), apart from other weaker radiostained bands in each extract. The binding of IgE to 200 and 90 kDa allergens from pork kidney was inhibited by gut from pork and lamb in immunoblotting inhibition assays. No inhibition was produced by pork meat.

CONCLUSIONS

A mechanism of IgE-mediated hypersensitivity has been demonstrated in this case of anaphylaxis provoked by pork products. Four main allergens were detected in pork kidney, two of which (200 and 90 kDa) share allergenic epitopes with proteins from pork and lamb gut. On the other hand, pork meat does not seem to have allergenic epitopes in common with pork kidney.